May 11th, the day after Reinhard’s birthday.
Jin was on Hourai Island, reviewing the progress of the spaceship’s construction.
The site was a vast stretch of level ground behind the laboratory, which had been cleared and graded to serve as a spaceport.
The area spanned approximately eighteen square kilometers—a rectangle three kilometers by six kilometers—with a construction dock situated at the eastern end.
A massive storage facility stood at the western end, housing various aircraft; the taxidermied Frost Dragon was also on display inside that building.
Inside the construction dock, the sight of the heavy-duty golems Daidara 1 through 50 working in unison was a spectacle in itself.
"The outer hull is multi-layered, then?"
"Yes, My Lord. It is the ship's most vital component," Laozi explained as he approached.
"From the exterior inward, the layers consist of magi-invar, foamed Ground Spider resin (GSP), mithril, magi-resin, and 64 light silver."
He clarified that the foamed Ground Spider resin provided insulation, while the magi-resin was intended for emergency repairs in the event of a puncture.
"We are also adding an inner lining of hyper-adamantite to the command room and My Lord's private quarters."
Laojun was nothing if not thorough when it came to Jin’s safety.
The explanation continued, noting that the ship was equipped with five Warp Gates for emergency evacuations and five times the required number of barrier projectors.
"I wonder if there is anything else we’ve overlooked."
Once Laozi finished his report, Jin returned to the laboratory and sat in the workshop with Reiko, lost in thought.
"Father, what is the plan for the magi-brain that will control the spaceship?" Reiko asked.
"Ah, right. Laojun, what is the status on that?"
Laojun replied immediately.
『Yes, My Lord. We intend to install a dedicated magi-brain, but if possible, I would like for you to craft it yourself, My Lord.』
Laojun operated under several limiters, meaning he could not simply build anything he wished. Specifically, the creation of anything entirely new or anything that surpassed current technological standards required Jin’s explicit authorization. Combining existing technologies, however, was generally permitted.
"I see. Are there any other requests?"
『Yes. I believe it would be wise for you to consult with No. 700672 once more.』
As far as Jin knew, No. 700672 was the most knowledgeable being in existence.
"Good point. He might have advice regarding the spaceship as well. Let’s head over right away."
Taking Reiko with him, Jin traveled to No. 700672’s base via Warp Gate.
＊ ＊ ＊
"You are welcome, Jin-dono."
No. 700672 greeted Jin with his usual composure. At his sides were the 'White girl' Neige and the 'Red-eyed girl' Rouge, both nestled close to him.
"You seem well."
"Indeed. I have been receiving regular supplies of Persica juice. It appears your own body has fully acclimated to this world as well."
"Yes, thanks to you."
After exchanging these pleasantries, Jin moved to the main topic.
"The truth is, I am currently building a spaceship."
"Oh? You have finally reached that stage."
"Yes. And so, if you wouldn't mind, I was hoping you might have some words of caution for me."
No. 700672 paused to consider the request.
"...I see. It is hardly a conversation for standing around. Come this way."
Jin and Reiko followed him to a table at the back of the room.
"To begin with, this very room is part of the Heavenly Ship," No. 700672 began slowly. "Imagine for a moment: if you were to dive into the deep ocean while blindfolded, what would be your greatest concern?"
Jin pondered the analogy. "...It would be vital to know my exact position."
"Precisely. That is the correct answer."
"I suppose that means we need to constantly track the positions of Ars and the Sun."
"Exactly. Furthermore, should you lose sight of them, you must have a way to find them again."
Jin was glad he had come; the advice was already proving invaluable.
"Furthermore, an autopilot is essential. It would be disastrous if the ship could not be piloted while you slept or were otherwise occupied."
Jin nodded; it was a common-sense point he hadn't fully prioritized.
"You must also account for the possibility of zero-gravity—or more accurately, a state of weightlessness."
"Which means all equipment should be fixed in place as a rule."
"Indeed." No. 700672 added that magnets could be used for certain items.
He also warned that colliding with space dust or meteorites during high-speed travel would cause immense damage. They should not rely solely on barriers but should also have a means of detecting obstacles in advance.
"A sort of object-tracking radar is necessary, then."
"Mm. Though it may be difficult to implement. Furthermore, there are times when it is better to destroy large objects rather than avoid them, so it would be wise to have weapons for such a purpose."
"Ah, you're right."
Jin had magi-cannons and Laser Cannons, but he lacked explosive weaponry.
"A bomb utilizing a Mana Explosion... a mana bomb. Or perhaps a missile equipped with a warhead..."
Jin’s creative drive was only growing.
Next, No. 700672 mentioned that if they intended to land on and investigate unknown celestial bodies like the Moon, a dedicated vehicle would be indispensable.
"There will surely be things that cannot be found from the sky alone."
"I understand."
A Capricorn 1 or even a Tortoise would do, but Jin wanted a vehicle capable of operating in a vacuum. A scout aircraft would also be necessary.
Furthermore, No. 700672 recommended having lifeboats for emergency evacuations.
"It goes without saying, but Space is dark. Ensure the ship has sufficient light within."
After receiving further advice on designing lifelines—ensuring water, food, and air (oxygen) had ample safety margins—Jin was given a final word.
"If you reach an impasse, you may visit at any time."
With those words, Jin returned to Hourai Island, feeling that the meeting had been immensely productive.
＊ ＊ ＊
"Welcome back."
When Jin returned to Hourai Island, Elsa was there to greet him.
Lately, Elsa spent her mornings in Kaina Village, teaching the children alongside Mine or assisting Sally at the clinic.
"I'm back."
"I heard from Laojun—did you go to see No. 700672?"
"Yeah. He gave me a lot of advice."
Jin walked her through the suggestions he had received for the spaceship’s construction.
"His advice is always so helpful....Jin, may I suggest one thing as well?"
"Of course."
"If you're going to build a medical bay, I'd like you to provide a redundant power system for the climate control, gravity, and lighting."
"That makes perfect sense."
Jin agreed; increasing the reliability of facilities where lives were at stake was an absolute necessity.
"...Now that I think about it, it might be a good idea to ask the other members of the Jin Family for their input as well."
Jin reminded himself not to become narrow-minded in his designs.
"Yes, I agree," Elsa said with a smile.
『My Lord, please do exactly that,』 Laojun added his support as well.